Maven: Project management tool (for Eclipse)

Following our target, create a XP Software Development Environment, today we add another tol for the box.

Maven is a project management tool with the following main features:

• Convention over configuration: it provides many estructural standards for the project in order to make easy the development, and avoid problems with many configuration files:
  • ${basedir}/src/main/java: your code
  • ${basedir}/src/main/resources: configuration resources
  • ${basedir}/src/main/webapp: web, css, html, jsp … files
  • ${basedir}/src/test: test classes
  • ${basedir}/target/classes: compiled classes
  • ${basedir}/target: jar, war, ear…. for packages
  • ….
• Manage all life cycle steps for the project:
  • Very simple Life Cycle: Compiling –> Test –> Packaging
  • In every life cycle steps you can execute goals. In packaging for example: mvn jar:jar
• Manage the dependencies with other projects, this is the feature that takes my attention:
  • Forget download jar libraries for spring, hibernate, configure them in Java Buil Path,….. bad stuff. Solution: write your dependencies in pom.xml, and it download them and makes the Build path.
  • The Archetypeeeees ¡¡¡¡ They are application skeletons with preconfigured pom.xml to develop projects like grails, seam, roo,… Take a look at Appfuse and this archetypes when you will create a project with maven in eclipse.
• Have a plugin ecosystem to execute goals for all the phases in every kind of project.

Furthermore in my case gives some fundamental features:

• Full Elcipse integration (M2Eclipse).
• Good documentation: Maven the Definitive Guide and m2eclipse Documentation.
• It integrates our projects easy with other XP tools like Continuous Integration, TDD, code analizers,…

Install with the following instructions:

• Download Maven in a folder in your system: c:\dev\frameworks\maven2
• define this folder in PATH as M2_HOME. You can test it: mvn -v
• Eclipse installation Help > Install New Software > Add http://m2eclipse.sonatype.org/update/

For the begining we are going to make an example with Eclipse. Create a new project File > New > Other … > Maven > Maven Project. Mark “Create a simple project” to avoid archetypes now. Maven makes you fill Group Id, Artifact ID.

Create the following example Class:

package com.lebrijo.ejemploMaven;public class Hello {public static void main( String[] args )    {
 
        System.out.println( "Hello World!" );
 
    }
 
}

The command “mvn install” generate the jar that we execute with “java -cp target/simple-1.0-SNAPSHOT.jar com.lebrijo.ejemploMaven.Hello”. But in Eclipse you can execute as Java Application.

To add a dependency, right button over the project > Maven > Add dependencies:

We could use the Spring dependency injection making the search, and select the concrete version. After thar we update the libraries with right clic over the project > Maven > Update Dependencies.

This actiion generates the followin pom.xml file:

  	<dependency>
 
  		<groupid>org.springframework</groupid>
 
  		<artifactid>spring-context</artifactid>
 
  		<version>3.0.0.RELEASE</version>
 
  	</dependency>

Take the example project from the following link: Maven2 basic example.